The present invention relates to a powder hair dye composition. More specifically, the invention relates to a powder hair dye composition incorporating sodium percarbonate as an oxidizing agent and also incorporating a specific key intermediate and a coupler as an oxidation dye.
Conventionally, as hair dyes such as oxidation hair dyes, powder hair dyes have been provided. Powder hair dyes are usually one-agent type, and, at the time of use, they are dissolved in water, a water-based dissolving liquid of certain composition, or the like to form a paste, then applied to the hair, and left on for 30 to 40 minutes to perform a hair-dyeing treatment. Therefore, powder hair dyes can be produced, packaged, distributed, and stored in powder form, which is lightweight and easy to handle. This is advantageous in terms of cost as compared with hair dyes in cream form or solution form. Also for powder hair dye users, there are advantages in that, for example, the hair dye can be used in portions, is convenient to carry because of its light weight, and is easy to use.
A powder hair dye contains an oxidation dye and oxidizing agent in powder form, and usually also contains an alkaline agent in powder form. An oxidation dye may be composed only of a key intermediate, but is often composed of a key intermediate and a coupler. When an oxidation hair dye dissolved in water is allowed to act on the hair, melanin in the hair is decomposed by the action of the oxidizing agent, and also the oxidation dye is polymerized in the hair to form an oxidized dye polymer, whereby the hair is dyed to the desired hue. Persulfates, percarbonates, and the like are known as oxidizing agents. However, because persulfates are highly oxidative and may decompose the oxidized dye polymer, percarbonates such as sodium percarbonate are used in many cases.
The following PTL 1 discloses a powder hair dye composition containing an oxidation dye sulfate and sodium percarbonate that has a high active oxygen amount and is relatively highly oxidative, as well as a storage container having a configuration suitable for the storage thereof. The following PTL 2 discloses a powder hair dye composition containing an oxidation dye, an oxidizing agent such as sodium percarbonate, and a powdered silicone compound.